a, b, c = input().split()
digits = {"zero": 0, "one": 1, "two": 2, "three": 3, "four": 4, "five": 5, "six": 6, "seven": 7, "eight": 8, "nine": 9}
x = digits[a] * 100 + digits[b] * 10 + digits[c]
count = 0
for i in range(1, x + 1):
    if x % i == 0:
        count += 1
if count == 2:
    print(x)
else:
    for k_right in range(x + 1, 10000):
        count = 0
        for i in range(1, k_right + 1):
            if k_right % i == 0:
                count += 1
        if count == 2:
            break
for k_left in range(x - 1, 0, -1):
    count = 0
    for i in range(1, k_left + 1):
        if k_right % i == 0:
            count += 1
    if count == 2:
        break
if k_right - x < x - k_left:
    print(k_right)
else:
    print(k_left)
